Rework progressive render loop.

core/include/fpdfapi/fpdf_render.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef CORE_INCLUDE_FPDFAPI_FPDF_RENDER_H_
 #define CORE_INCLUDE_FPDFAPI_FPDF_RENDER_H_
 
 #include <map>
@@ skipping 131 matching lines @@
   void RenderStep();
 
   Status m_Status;
   CPDF_RenderContext* const m_pContext;
   CFX_RenderDevice* const m_pDevice;
   const CPDF_RenderOptions* const m_pOptions;
   std::unique_ptr<CPDF_RenderStatus> m_pRenderStatus;
   CFX_FloatRect m_ClipRect;
   FX_DWORD m_LayerIndex;
   FX_DWORD m_ObjectIndex;
+  CPDF_RenderContext::Layer* m_pCurrentLayer;
   FX_POSITION m_ObjectPos;
-  FX_POSITION m_PrevLastPos;
 };
 
 class CPDF_TextRenderer {
  public:
   static void DrawTextString(CFX_RenderDevice* pDevice,
                              int left,
                              int top,
                              CPDF_Font* pFont,
                              int height,
                              const CFX_ByteString& str,
@@ skipping 101 matching lines @@
  public:
   CPDF_RenderConfig();
   ~CPDF_RenderConfig();
   int m_HalftoneLimit;
   int m_RenderStepLimit;
 };
 
 FX_BOOL IsAvailableMatrix(const CFX_Matrix& matrix);
 
 #endif  // CORE_INCLUDE_FPDFAPI_FPDF_RENDER_H_